No. Loosely speaking, Zwave pretty strictly defines a list of device types (lightbulb, thermometer, etc) and supported formats for read/writes to it by device t

No. Loosely speaking, Zwave pretty strictly defines a list of device types (lightbulb, thermometer, etc) and supported formats for read/writes to it by device type (turn on/off, reports temperature,...). The API to handle those is then standardized, and the device manufacturer just fills in the code to implement the calls appropriate to the device. Devices are more-or-less "self-describing." Baseline Zigbee is a bit more freeform (it's not solely a home automation protocol) and is a transport for whatever data format manufacturers want to send, with devices implementing their own details on top. Later on there was an attempt to standardize the communication format for home automation similar to how Zwave works and it was somewhat successful, but manufacturers still have a bad habit of having deviations and quirks. The standard is also not as rigidly enforced like it is with Zwave. Again this is all simplified and there's more nuance but that's generally the breakdown. Practically speaking you'll have more consistency with Zwave devices, but nowadays Zigbee devices have a lot more variety. Support for (and quality of support for) new devices in Zigbee can be a bit more hit-or-miss, but it's usually pretty good nowadays with Zigbee having more marketshare/momentum. I use both, I have more problems with Zigbee, but I also have more devices for it by virtue of their being more choices.